1. Field of the Invention
The present invention relates to a brush member used in a transfer device that transfers, while supplying a transfer bias to a rear surface of a moving belt member using the brush member, a visible image on the surface of a latent image bearing member onto a front surface of the belt member or a transfer material held on the front surface. The present invention also relates to transfer devices and image forming apparatuses like a copying machine, a facsimile apparatus, and a printer that use such a brush member.
2. Description of the Related Art
Conventionally, in the image forming apparatuses of this type, in general, a transfer brush that has a predetermined electric resistance in a conductive brush unit including a plurality of raised bristles vertically provided on the surface of a metal support plate is used as a transfer brush serving as the brush member. As such image forming apparatuses, those disclosed in Japanese Patent Application Laid-Open Nos. 2000-347511, 2001-154499, 2001-331047, 2002-123124, 2002-169418, H9-281768, and the like are known. As the raised bristles forming the brush unit, raised bristles made of conductive rayon or nylon are used as disclosed in Japanese Patent Application Laid-Open No. H9-281768.
In the image forming apparatuses with such a constitution, shavings of the rear surface of the belt member due to rubbing of the belt member against the transfer brush accumulate on a brush tip of the transfer brush. The shavings change a frictional force of the transfer brush and the belt member to irregularly fluctuate a linear velocity of the belt member. This tends to cause transfer blurring in a transfer image.